Capacitive Rotary Control Element for Haptic Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Touch screens in motor vehicles lack haptic feedback, leading to wear and tear, unwanted noise, and accidental function activation due to mechanical rotary controls that protrude and slide on the smooth surface.
Innovation Solution
A control element with a rotatable, electrically conductive rotary element and contact elements on a carrier structure that can be immovably fastened to a capacitive surface, allowing haptic feedback and precise function selection without direct sliding contact, using a spring mechanism for confirmation and reducing friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If mechanical rotary controls protrude from the touch screen surface to provide haptic feedback, then the user can perceive functions haptically and maintain focus on traffic situation, but the sliding contact between the control element and touch screen causes wear and damage, creating scratches and furrows on the surface
Solution Approach 1:
A capacitive membrane is introduced as an intermediary layer between the rotary control element and the touch screen surface. This membrane is electrically conductive and can be deformed by the rotary element, allowing capacitive coupling with the touch screen without direct mechanical contact. The membrane absorbs the mechanical stress and prevents wear on both the touch screen and rotary element, while still enabling haptic feedback through its deformation.
Solution Approach 2:
The direct mechanical sliding contact between the rotary element and touch screen is replaced with a capacitive coupling system. The rotary element acts as a capacitive sensor that couples to the touch screen through the deformable membrane, transforming the mechanical interaction into an electrical field interaction. This eliminates friction and wear while maintaining haptic feedback through membrane deformation.
2Measurement precision
If mechanical rotary controls slide on the touch screen surface, then angular position can be detected, but friction causes unwanted noises during rotation
Solution Approach 1:
The mechanical sliding contact that generates noise is replaced with a capacitive sensing system. The rotary element creates capacitive coupling with the touch screen through the membrane, allowing angular position detection through changes in capacitive coupling rather than through mechanical friction. This eliminates the source of noise while preserving the ability to detect rotational position.
3Ease of operation
If the rotary element is in direct contact with the capacitive surface during rotation, then functions can be controlled, but accidental settings can be activated briefly due to unwanted contact with different areas
Solution Approach 1:
The deformable capacitive membrane serves as a mediator that localizes the capacitive coupling to a specific area. When the rotary element rotates, it deforms the membrane in a controlled manner, creating capacitive coupling only with the intended target area on the touch screen. The membrane's elasticity ensures that the coupling area remains well-defined, preventing accidental activation of adjacent functions.
4Ease of operation
If sliding contact is used between rotary control and touch screen, then control function can be implemented, but electrical charges are no longer reliably transferred through the element
Solution Approach 1:
The electrical charge transfer mechanism is changed from direct conductive contact through friction and pressure to capacitive coupling through the deformable membrane. The membrane, being electrically conductive, allows electrical field interaction between the rotary element and touch screen without requiring sustained mechanical pressure. This capacitive coupling provides reliable signal transfer even with minimal contact force, eliminating the reliability issues of charge transfer through sliding contact.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides haptic feedback and precise function selection on a capacitive surface while minimizing wear and tear, reducing accidental settings and noise, and ensuring reliable electrical contact.
Implementation Method 1
control element comprises at least one electrically conductive area... The rotary element preferably comprises an electrically conductive material on the outer surface thereof which is touched by a user during the use of the control element
Data Source
AI summary
Disclosed herein is a control element, which can be arranged on a capacitive surface, for controlling a function of the capacitive surface, comprising a carrier structure, a rotary element rotatable about an axis of rotation with respect to the carrier structure, comprising at least one electrically conductive area, at least one electrically conductive contact element arranged on the carrier structure, wherein the contact element comprises a contact area which is arranged at least in some areas on an underside of the control element, so that the contact area, when the control element is arranged on the capacitive surface, is arranged at least partially touching the capacitive surface, wherein the electrically conductive area of the rotary element is in contact with a contact element in at least one rotational position of the rotary element. The rotary element can be moved along the axis of rotation with respect to the carrier structure.